Hydraulic jacks, especially large tonnage jacks, are prone to oil corrosion inside the cylinder, leading to premature rusting. It is necessary to frequently disassemble the jack and inspect the internal cylinder components. Regarding the disassembly process and steps, the following methods can be referred to:

1. Turn the switch to the landing position, place the gasket, and gently hammer down with a hammer to keep the jack down to the bottom,

2. Gently tap the base, not too close to the side, and strike once. There is a gap between the oil cylinder and the base. Use pliers to clamp the jack, and use appropriate tools to unscrew the cylinder head. There are two types of tools, one is an iron ring with an iron rod, and the other is an F-shaped iron rod. Rotate the cylinder head clockwise to remove the sealing ring;

3. Using an F-shaped iron rod, clamp the quick insert on the oil cylinder, and the heavy cylinder head is smoothly removed. Gently tap the outer shell with brass to ensure that the cylinder head is not damaged,

4. If the top of the cylinder head is worn and deformed, it needs to be first polished with a hand grinding wheel to remove the protruding part. If it is not polished, it cannot be forcibly removed and installed. After grinding it flat, knock out the small cylinder of the middle cylinder. For the missing corner, it can be welded and polished again. The small hole on the middle cylinder will participate in the lowering work of the hydraulic jack, so it cannot be blocked. Then use a flat iron pipe to remove the clip and remove the small cylinder.